Radial infeed thread rolling offers the advantage of balanced loading of the work and minimizes spindle loads. It also allows rolling at greater distances from the work holding collet. Many radial infeed thread rolling attachments accommodate limited ranges of stock sizes. Other thread rolling attachments expand their stock size range through the use of a large number of adjustment cams. There exists a need for an expanded range, continuously adjustable thread rolling attachment which employs a limited number of cams and provides an actuation system with a stiffness and penetration control consistent with the roll form process.